Apparatus and method for advancing catheters or other medical devices through a lumen

ABSTRACT

Devices, systems, and methods are disclosed that help deliver catheters or other medical devices to locations within a patient&#39;s body. The device includes a transporter catheter having a proximal end and a distal end, at least a first balloon located at the distal end, substantially at a tip of the transporter catheter, and at least a second balloon located between the distal end and the proximal end of the transporter catheter. The first balloon is an orienting balloon and the second balloon is an anchor balloon. The transporter catheter may include a single lumen or more than one lumen. The transporter catheter may include a shaft including an inner layer and an outer layer, the inner layer may be made of a material more flexible than the material of the outer layer. The outer layer may also include a braided-wire assembly, said braided-wire assembly being formed by braiding a plurality of flat wires or circular wires. The braided-wire assembly may wrap around the inner layer. The transporter catheter may include a shaft that may include a plurality of segments of varying degrees of hardness. The degree of hardness of the segment of the shaft of the transporter catheter located between the first balloon and the second balloon may be less than the degree of hardness of the segment of the shaft between the second balloon and the proximal end of the catheter.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. patent application Ser. No. 16/721,909, filed Dec. 19, 2019, which is a continuation-in-part of co-pending U.S. patent application Ser. No. 16/701,966, filed Dec. 3, 2019, and claims benefit of U.S. Provisional Application No. 62/886,349, filed Aug. 14, 2019; the entire content of the above applications is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates generally to devices, systems, and methods that help deliver catheters or other medical devices to locations within a patient's body. More particularly, the present invention is directed to a transporter catheter, which is located inside an outer catheter, e.g., a sheath, an introducer catheter, a guide catheter or an inner catheter. An orienting balloon at a tip of the transporter catheter assists in the orientation and positioning of the transporter catheter, and an anchor balloon is used for anchoring the transporter catheter, e.g., anchoring the transporter catheter to an inner surface of a sheath or an introducer catheter or a guiding catheter or an inner catheter as the user maneuvers the system comprising the transporter catheter and the sheath or the introducer catheter or the guiding catheter through the patient's body.

BACKGROUND OF THE INVENTION

Catheters are used for an ever-growing number of medical procedures including diagnostic and/or therapeutic procedures. To facilitate placement of the diagnostic and/or therapeutic catheter at a location of interest within a patient, a catheter may be introduced through a second catheter, which is commonly known as a “sheath” or “introducer catheter,” and these two terms will be used interchangeably herein. An introducer catheter is a tube that is used to facilitate the placement of other catheters into specific areas of the patient's body. In the field of cardiac ablation, for example, introducer catheters may be used to negotiate the patient's vasculature such that an ablation device may be passed through and positioned to be able to ablate arrhythmia-causing cardiac tissue. The introducer catheter itself may be advanced over a guidewire.

Complex coronary anatomy including tortuosity, calcification, as well as other structural characteristics of the coronary artery can make transit of hardware through the lumen proximal to a stenosis difficult and sometimes impossible. Several advancements in technology such as stiffer guidewires, large bore guide catheters that allow for improved passive support, and hydrophilic coatings that provide reduced friction, have improved the ability to advance balloons and stents through these coronary arteries with some success. Guidewires that allow for dynamic deflection of the tip such as the “Wiggle” wire have also improved hardware transit. However, even with these advances, in view of the expanding indications for percutaneous coronary intervention (“PCI”), there is an unmet need for improving PCI outcomes in complex substrates.

A guide catheter may be located inside an introducer catheter, and an inner support catheter (“daughter” or “child” catheter) placed inside a guide catheter. Advancing the inner support catheter into the coronary artery deeply intubating the proximal coronary-artery lumen has been shown to improve support of the guide catheter and inner catheter composite system, thereby providing an opportunity for improved success for device advancement through a difficult coronary lumen (Guideliner, Guidezilla, Telescope). Frequently, these inner catheters are only able to navigate the proximal simpler portions of the artery anatomy, and do not allow the operator to obtain a position in the artery lumen that provides sufficient support to the guide catheter and inner catheter composite system. The inability to advance these inner catheters further into a patient's vasculature is frequently as a result of the “razor effect” caused by an overhang or transitions between the guidewire and the inner-support catheter.

Generally, it is known that the introducer catheter must have an overall diameter small enough to negotiate through a lumen of a vessel while retaining an inner diameter (or “bore size”) large enough to accommodate a diagnostic, a therapeutic and/or an ablation device therethrough. Furthermore, since the path within a patient's vessel is often long and tortuous, steering forces must be transmitted over relatively long distances. Accordingly, it is desirable for the introducer catheter to have enough axial strength to be pushed through the patient's vasculature via a force applied at its proximal end (“pushability”). It is also desirable for the introducer catheter to be capable of transmitting a torque applied at the proximal end through to the distal end (“torqueability”). An introducer catheter should also have enough flexibility to conform substantially to the patient's vasculature and yet resist kinking as it conforms to the patient's vasculature. These various characteristics are often in conflict with one another, with improvements in one often requiring compromises in others. For example, increasing the bore size of an introducer catheter having a given overall diameter requires utilizing a thinner wall. As catheters are used in smaller and smaller passages and vessels, there is a growing need to use introducer catheters that have a smaller outer dimension. However, a thin-walled introducer catheter is more likely to collapse upon itself or kink when a torque or a push force is applied at its proximal end.

In order to facilitate the advancement of an introducer catheter (or an introducer sheath) through a patient's vasculature, the application of a push force and/or torque at the proximal end of the introducer catheter and the ability to orient selectively the distal tip of the introducer catheter in a desired direction can permit medical personnel to advance the distal end of the catheter and to position the distal portion of the introducer catheter at a location of interest.

During use, an introducer catheter shaft should be capable of transmitting torque and resisting compression. Substantial frictional forces sometimes resist transmission of axial forces and torque along the length of the introducer catheter. In some cases, these forces may cause the introducer catheter shaft to twist about a longitudinal axis of the introducer catheter shaft, storing energy in the process in a spring-like fashion. If such energy is released suddenly, the distal end of the introducer catheter, which may have been deflected by a steering mechanism, may be undesirably propelled with significant force.

With respect to resisting compression during use, it is important that users be able to advance the introducer catheter through a vessel, sometimes against significant frictional resistance, without undue axial or radial compression or snaking or fish-mouth distortion of the introducer catheter shaft. Shaft compression may complicate the positioning of the distal end of the introducer catheter shaft at a desired location for a medical procedure. In addition, medical personnel may rely on tactile feedback to attain and verify proper positioning of the introducer catheter, and such feedback can be impaired by excessive compressibility.

Accordingly, there is a need for improved devices, systems and methods to deliver an introducer catheter or a sheath or a guide catheter or an inner catheter at a location of interest within a patient's body via a body lumen without damaging the lumen, or a body vessel, including a tortuous lumen or vessel. The foregoing discussion is intended only to illustrate the present field and should not be taken as a disavowal or limitation of claim scope.

SUMMARY OF THE INVENTION

The devices, systems, and methods for negotiating a patient's vasculature through lumens or vessels are described herein. In particular, the present invention provides improved devices, systems, and methods for procedures including diagnostic, therapeutic, and ablative procedures in arterial and venous systems, as well as for non-vascular lumen and vessel. A catheter system of the present invention comprises a transporter catheter and an introducer catheter. In an exemplary embodiment, a balloon at a distal tip of a transporter catheter facilitates the negotiation of the transporter catheter and/or associated device or system through the body lumens of a patient. The transporter catheter may have at least one anchor balloon that anchors the transporter catheter to the introducer catheter. The anchor balloon prevents partially or fully the slippage or “pushback” of the transporter catheter backwards into the lumen of the introducer catheter when the orienting balloon of the transporter catheter experiences increased resistance within the vasculature in the patient's body. Also, when the anchoring balloon is located proximate to the orienting balloon, the anchoring balloon acts as a stopper to prevent the orienting balloon from backing into the lumen of the introducer catheter as the catheter system is being maneuvered through the vasculature of the patient's body. It also prevents the orienting balloon from migrating fully out of the introducer catheter, guide catheter or inner catheter when forward force is applied to the catheter system. In the description of the invention, the transporter catheter is described as being located inside the introducer catheter. The transporter catheter may also be located inside any outer catheter, e.g., a sheath, a mother catheter, a guiding catheter or a daughter catheter, to advance the outer catheter. An orienting balloon at a tip of the transporter catheter assists in the orientation and positioning of the transporter catheter, and an anchor balloon is used for anchoring the transporter catheter, e.g., anchoring the transporter catheter to an inner surface of an outer catheter as the user maneuvers the system comprising the transporter catheter and the outer catheter through the patient's vasculature. The description and discussion regarding advancing the introducer catheter also applies to advancing any other outer catheter through a patient's vasculature using a transporter catheter.

The catheter system of the present invention may be advanced through the vasculature of a patient's body by (a) pushing and/or torqueing the introducer catheter, (b) pushing and/or torqueing the transporter catheter, or (c) pushing and/or torqueing both the introducer catheter and the transporter catheter. If the user pushes and/or torques the introducer catheter to advance the catheter system through the vasculature of the patient's body, then the anchor balloon of the transporter catheter pushes and/or torques the transporter catheter as the catheter system moves through the vasculature of the patient's body. If the user pushes and/or torques the transporter catheter to advance the catheter system through the vasculature of the patient's body, the anchor balloon of the transporter catheter pulls and/or torques the introducer catheter as the catheter system moves through the vasculature of the patient's body. In both cases, the orienting balloon assists in orienting and maneuvering the catheter system through the vasculature of the patient's body.

An embodiment of the invention provides devices, systems, and methods including a transporter catheter comprising a first tube having a length and defining a first open interior lumen, the first open interior lumen connected to a first balloon located at a distal end of the transporter catheter, a second tube having a length and defining a second open interior lumen, the second open interior lumen connected to a second balloon located between the first balloon and the proximate end of the transporter catheter. In another embodiment, the second balloon is proximate to the first balloon. In yet another embodiment, the distance between the proximal end of the first balloon and the distal end of the second balloon is less than half the length of the fully inflated first balloon. In another embodiment, the distance between the proximal end of the first balloon and the distal end of the second balloon is less than half the diameter of the fully inflated first balloon. In one embodiment, the orienting balloon has length in the range from 15-40 mm. In another embodiment, the orienting balloon expands to diameters ranging from 1.5-6 mm after inflation. In yet another embodiment, the orienting balloon expands to diameters in the range of 6-12 mm upon inflation.

In one embodiment of the invention, the device comprises a transporter catheter having a proximal end and a distal end, at least a first balloon located at the distal end, substantially at a tip of the transporter catheter, and at least a second balloon located between the distal end and the proximal end of the transporter catheter. The first balloon is an orienting balloon and the second balloon is an anchor balloon. The transporter catheter may include a single lumen or more than one lumen. In one embodiment, the shaft of the transporter catheter may be made from a polymer such as polytetrafluoroethylene (PTFE) or PEBAX (polyether block amide). In another embodiment, the shaft of the transporter catheter may comprise a wire-based reinforcement embedded in the polymeric shaft. In another embodiment, the shaft of the transporter catheter may comprise an inner layer and an outer layer. In one embodiment, the inner layer may be made of a material more flexible than the material of the outer layer. In another embodiment, the outer layer comprises a material that has a lower flexural modulus and a higher-yield strain than the material of the inner layer. In one embodiment, the outer layer may comprise braided-wire assembly, said braided-wire assembly being formed by braiding a plurality of flat wires or circular wires. The shaft of the transporter catheter may comprise a plurality of segments of varying hardness characteristics. The hardness of the first segment of the shaft of the transporter catheter located between the orienting balloon and the anchor balloon may be less than the hardness of the second segment of the shaft between the anchor balloon and the proximal end of the catheter. In another embodiment, the hardness of a portion of the first segment of the shaft proximate to the orienting balloon may be less than the hardness of a portion of the first segment of the shaft proximate to the anchor balloon.

Another embodiment of the invention provides devices, systems, and methods that comprise an introducer catheter that has a capability to maneuver through the vasculature of a patient's body independently from the transporter catheter. Such introducer catheters are generally known as “steerable-guide” catheters. One embodiment of the steerable-guide catheter comprises at least a first handle assembly comprising a first deflecting mechanism coupled to a distal end portion of the steerable-guide catheter to apply a deflecting force to bend the distal end portion, the first deflecting mechanism adapted to bend the distal end portion in a first articulated position, and a second deflecting mechanism coupled to the distal end portion of the steerable-guide catheter to apply a deflecting force to bend the distal end portion, the second deflecting mechanism adapted to bend the distal end portion in a second articulated position. The steerable-guide catheter further comprises at least an open interior lumen to accommodate passage of a transporter catheter to assist in the orientation and positioning of the steerable catheter. The transporter catheter located inside the steerable-guide catheter assists in orienting and positioning the steerable catheter and compliments the functioning of the deflecting mechanisms to advance the steerable catheter smoothly. After the steerable-guide catheter is positioned at the desired location, the orienting balloon and the anchor balloon in the transporter catheter are deflated and the transporter catheter is removed from the interior lumen of the steerable-guide catheter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a transporter catheter in accordance with one embodiment of the present invention.

FIG. 2 is a perspective view of a transporter catheter having a first segment of the transporter catheter that is more flexible than a second segment of the transporter catheter.

FIG. 3 is a perspective view of a transporter catheter having multiple segments of the transporter catheter with multiple degrees of flexibility.

FIG. 4a is a perspective view of a transporter catheter showing a contoured orienting balloon that facilitates smooth movement of the orienting balloon by reducing drag.

FIG. 4b is a perspective view of a transporter catheter showing a perfusion lumen to perfuse blood across the anchor balloon when the anchor balloon is inflated.

FIG. 4c is a perspective view of a transporter catheter showing a perfusion lumen to perfuse blood across the orienting balloon when the orienting balloon is inflated.

FIG. 5 is a perspective view of a transporter catheter with more than one anchor balloons.

FIG. 6 is a perspective view of a transporter catheter having multiple segments of varying degrees of hardness, with an anchor balloon present on more than one segment.

FIG. 7 is a perspective view of a transporter catheter having a hydraulic system to advance the transporter catheter.

FIG. 8a-d are perspective views of modifications to the surface of the anchor balloon to enhance anchoring to the inner surface of an introducer catheter.

FIG. 9 is a perspective view of a catheter system comprising a transporter catheter and an introducer catheter advancing through a vasculature of a patient's body.

FIG. 10a-b is a schematic of forces acting on a wall of an introducer catheter when it is pushed at its proximal end or pulled at its distal end.

FIG. 11 is a perspective view of a catheter system comprising a mother catheter, an inner support catheter and a transporter catheter advancing through an adverse arterial lumen.

FIG. 12 is a perspective view of a catheter system comprising a mother catheter, an inner support catheter and a transporter catheter that has advanced through an adverse arterial lumen.

FIG. 13 is a perspective view of positioning of a stent in an adverse arterial lumen using a catheter system comprising a mother catheter, an inner support catheter and a transporter catheter.

FIG. 14a-d are perspective views of modifications to the surface of the proximal portion of balloon to enhance anchoring of the proximal portion of the balloon to the inner surface of an introducer catheter.

FIG. 15 is a perspective view of a transporter catheter having a balloon with a surface at its distal portion configured for smooth movement through a patient's vasculature and a surface at its proximal portion configured for anchoring to an outer catheter.

FIG. 16 is a perspective view of a transporter catheter having a balloon having a diameter at a distal portion which, upon inflation, is greater than an outer diameter of the outer catheter.

FIG. 17 is a perspective view of a transporter catheter having two balloons, a first balloon with a surface at its distal portion configured for smooth movement through a patient's vasculature and a surface at its proximal portion configured for anchoring to an outer catheter, and a second balloon for additional anchoring to the outer catheter.

FIG. 18a-d are perspective cross-sectional views of shaft of some embodiments of a transporter catheter.

FIG. 19 is a perspective sectional view of a distal end portion of an embodiment of a transporter catheter that is steerable using pull-wires.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention are described below with reference to the accompanying drawings. Systems using transporter catheters according to the present invention provide improved maneuverability, flexibility, and kink resistance.

In reference to FIG. 1, catheter 100, comprises a shaft 101, having a proximal end 102, and a distal end 103, and a first lumen 104, a second lumen 105, and a third lumen 106. First lumen 104 extends substantially the entire length of said shaft 101 and communicates with an orienting balloon 107 located at about the distal end 103 of said shaft 101. Second lumen 105 extends the entire length of said shaft 101 and allows for the placement of catheter 100 over guidewire 108. Third lumen 106 communicates with an anchor balloon 109, which is located between the orienting balloon 107 and the proximal end 102 of the shaft 101. In one embodiment, the anchor balloon is located proximal to the orienting balloon. In another embodiment, the first lumen 104 and the third lumen 106 are diametrically opposed and each lumen extends substantially parallel to the longitudinal axis of the shaft 101. In another embodiment, the first lumen 104 and the third lumen 106 are symmetrically disposed on either side of a longitudinally extending plane bisecting the shaft into a first hemicylindrical portion and a second hemicylindrical portion.

In another embodiment, the third lumen 106 communicating with the anchor balloon may be adapted to receive a removable stiffening stylet to ease insertion by stiffening the catheter shaft. In yet another embodiment, two removable stiffening stylets may be inserted, one inserted in lumen 104 and another inserted in lumen 106. Stiffening stylet(s) are inserted to extend substantially the entire length of member 101 until just proximal to anchor balloon 109. If two stylets are used, the practitioner may insert one stylet further than the other to adjust the amount of stiffness as desired. In one embodiment, a stylet is not inserted beyond the anchor balloon.

Lumens 104, 105 and 106 are attached to Luer connectors 111 at their proximal end. Said Luer connectors are then connected to syringes, valves etc. to provide for the introduction of balloon inflation media. In one embodiment, a radiopaque marker may be located along shaft 101, including distal end 103. In another embodiment, a radiopaque marker may be located on the anchor balloon 109. In one embodiment, an imaging marker is fixed to shaft 101 at its distal end portion, disposed slightly proximal from the tip 103 and in the area proximate to a front-end portion of the orienting balloon 107. In another embodiment, the imaging marker is fixed on the orienting balloon 107. In yet another embodiment, the imaging marker is fixed on the anchor balloon 109. In one embodiment, the imaging marker is formed from a radiopaque material (e.g., gold, platinum, tungsten or alloys of these metals or from a silver-palladium alloy, or a platinum-iridium alloy). By so doing, it is possible to confirm the location of the catheter and then to advance the catheter 100 through a patient's vasculature, while monitoring such advancement using radiographic imaging and visualization. In one embodiment, the shaft of the transporter catheter may have a lumen from its proximal end to its distal end to infuse medication at the distal end by using a Luer connector at the proximal end.

The mechanical properties of segments of shaft 101 can be varied by adjusting and varying the properties of the cylindrical-braid structure(s) and the polymeric materials (e.g., the dimension of the cylindrical-braid structure and/or durometers of the polymers). Additionally, the mechanical properties of the segments of shaft 101 can be varied along the length of the shaft 101 in accordance with certain embodiments of the disclosure or can be substantially uniform along the entire length of the shaft 101 in accordance with other embodiments of the disclosure. In another embodiment, the shaft 101 is a monolithic elongate tubular shaft member having an inner core made of a first material and an outer layer made of a second material, the first material of the inner core defining lumens 104, 105 and 106 therein, the cross-sectional dimension of the first lumen 104 being uniform along the length of the first lumen 104, the cross-sectional dimension of the second lumen 105 being uniform along the length of the second lumen 105, and the cross-sectional dimension of the third lumen 106 being uniform along the length of the third lumen 106. In one embodiment, the tubular shaft member has an outer cross-sectional dimension that varies along the length of the tubular shaft member, the outer cross-sectional dimension being greater at the proximal end than at the distal end.

In one embodiment, the shaft 101 may be provided with a rigidity-imparting structure. In one embodiment, the rigidity-imparting structure is provided using a blade. The blade may be formed of a metal wire or a synthetic-resin wire. In another embodiment, as shown in FIG. 2, the rigidity-imparting structure is provided to the shaft over the entire length 201 of the shaft, except for the distal end portion 202 of the shaft from the anchor balloon 209 to the orienting balloon 207. The anchor balloon 209 anchors the rigidity-imparted structure 201 to the inner surface of a lumen of the introducer catheter 224. In another embodiment, the rigidity-imparting structure is provided to the shaft 101 in a range from the proximal end 102 of the transporter catheter to the distal end 115 of the anchor balloon 109. In one embodiment, the shaft of the transporter catheter has a stiffness and a resistance to kinking. In another embodiment, the shaft of the transporter catheter comprises an inner layer made preferably of a lubricious material, such as polytetrafluoroethylene (PTFE), and an outer layer made preferably of a thermoplastic elastomer, such as PEBAX (polyether block amide). In another embodiment, the inner and the outer layers are made of two different melt-processable polymers. In another embodiment, the shaft of the transporter catheter may comprise more than two layers. In another embodiment, the inner and/or the outer layer comprises a particulate radiopaque filler material. In another embodiment, the outer surface of the shaft of the transporter catheter may have at least one radiopaque strip along the length of the shaft and/or radiopaque markers at specific locations of the shaft, e.g., at the distal end of the transporter catheter.

In one embodiment, a wire-based reinforcement is embedded in the outer layer. The wire-based reinforcement may be in the form of a plait matrix or a helical coil. The plait matrix may be braided. The plait-matrix layer or the helical-coil layer may be bonded to the inner layer e.g., by melting in place. In one embodiment, a plait-matrix layer or a helical-coil layer is bonded to the inner layer by melting in place using a temporary shrink-wrap tubing as a forming member. The plait-matrix layer or the helical-coil layer may also be known as the torque-transfer layer. In another embodiment, the shaft comprises a plurality of sections with wire reinforcement in a form of a plait-matrix or a helical-coil layer extending continuously along at least one length from the proximal end 102 of the shaft. In another embodiment, the shaft comprises a plurality of sections with the plait-matrix layer or the helical-coil layer extending continuously from the proximal end 102 of the shaft to the distal end 115 of the anchor balloon 109. In another embodiment, the shaft comprises a plurality of sections with the plait-matrix layer or the helical-coil layer extending continuously from the proximal end 102 of the shaft to the proximal end of the orienting balloon 107.

The plait matrix or the helical coil may be made of round wires, elliptical wires, flat wires or combination thereof. Wires of any other cross-sectional shapes may also be used. The wires may be made from various materials, and may each be made of the same materials or materials with similar material properties, or different materials having different properties. As an example, such wires may be formed from stainless steel. The material of wires may be stiffer than the plastic materials forming the wall of the shaft. In one embodiment, the flat wire is at least about 0.003″ thick by about 0.007″ wide. In another embodiment, the wires may be made of Nitinol. In one embodiment, the braided-wire plait matrix has a proximal portion and a distal portion, the braided-wire plait matrix has a first density at the proximal portion and a second density at the distal portion, and wherein the first density differs from the second density, the density of the braided-wire assembly being measured in pixels of braids per inch of the shaft's longitudinal axis (PPI). In another embodiment, the PPI at the proximal portion of the braided-wire plait matrix is greater than the PPI at the distal portion of the braided-wire plait matrix. In another embodiment, the PPI is between about 10 and about 90. In yet another embodiment, the PPI is between about 5 and about 50. In another embodiment, the shaft of the transporter catheter comprises braided-wire plait matrix, wherein the PPI varies gradually from the proximal portion to the distal portion of the shaft whereby the stiffness of the shaft diminishes gradually from the proximal portion to the distal portion. In another embodiment, the braided-wire plait matrix wraps around the inner layer of the shaft. In another embodiment, the helical coil of wire wraps around the inner layer of the shaft. In yet another embodiment, the pitch of the helical coil at the proximal portion of the shaft is smaller than the pitch of the helical coil at the distal portion of the shaft. In another embodiment, the shaft of the transporter catheter comprises a helical coil of wire, wherein the pitch increases gradually from the proximal portion to the distal portion of the shaft whereby the stiffness of the shaft diminishes gradually from the proximal portion to the distal portion.

The torque-transfer layer may be made of stainless steel (304 or 316) wire or other acceptable materials known to those of ordinary skill in the art. In one embodiment, the torque-transfer layer is formed of a braided wire assembly comprised of flat wires, preferably stainless-steel wires including, for example, high tensile stainless-steel wires. The torque-transfer layer may be formed in any combinations of braid patterns, including one-over-one (involving at least two wires) or two-over-two (involving at least four wires) crossover patterns. In one embodiment, the torque-transfer layer may utilize a varying braid density construction along the length of the transporter catheter. For example, the torque-transfer layer may be characterized by a first braid density at the proximal end of the transporter catheter and then transition to one or more braid densities as the torque-transfer layer approaches the distal end of the transporter catheter. The braid density of the distal end may be greater or lesser than the braid density at the proximal end. In one embodiment, the braid density at the proximal end is about 50 PPI and the braid density at the distal end is about 10 PPI. In another embodiment, the braid density at the distal end is about 20-35% of the braid density at the proximal end. The torque-transfer layer may be formed separately on a disposable core and subsequently slipped around an inner liner. One or more portions of the torque-transfer layer may be heat-tempered and cooled before incorporation into the transporter shaft through methods that are known to those of ordinary skill. The action of heat tempering may help to release the stress on the wire and help to reduce radial forces. In another embodiment, the torque-transfer layer may be braided directly on the inner liner. In yet another embodiment, the torque-transfer layer may include at least one helical coil of steel wire. The distance between two consecutive spirals (known as the pitch) of the helical coil may vary along the length of the transporter catheter. For example, the torque-transfer layer may be characterized by a first pitch of helical coil at the proximal end of the transporter catheter and then transition to one or more pitches as the torque-transfer layer approaches the distal end of the transporter catheter. The pitch of the helical coil at the distal end may be greater or less than the pitch of the helical coil at the proximal end. In one embodiment, the pitch at the distal end is about 50-80% greater than the pitch at the proximal end.

In another embodiment of the invention shown in FIG. 3, the shaft has a first flexible portion 301 disposed at the distal end of the shaft, a second flexible portion 302, which is continuous with the first flexible portion 301 and flexible, but that has a higher degree of hardness than the first flexible portion 301, and a flexible portion 303, which is continuous with the second flexible portion 302 and that has a higher degree of hardness than the second flexible portion 302. In the embodiment shown in FIG. 3, the most flexible first flexible portion 301 is between the orienting balloon 307 and the anchor balloon 309. The second flexible portion 302 of the shaft is substantially covered by the anchor balloon 309. The third flexible portion 303 has a degree of hardness higher than the hardness of the second flexible portion and the first flexible portion and extends from the proximal end 102 of the catheter 100 to the proximal edge 116, 316 of the anchor balloon. The flexibility of transporter catheter becomes stepwise lower from its distal end to its proximal end. Because the portion 301 of the shaft proximate to the orienting balloon 307 is flexible, the orienting balloon 307 is capable of passing through a curved portion of a vessel with greater ease.

In one embodiment as illustrated in FIG. 4a , the distal end of the orienting balloon 407 is smooth and contoured to provide smooth movement of the orienting balloon. In another embodiment, the surface of the orienting balloon is coated with a friction-reducing coating. In another embodiment, the surface of the orienting balloon may have a wavy contour or other three-dimensional contours (not shown) when inflated to provide channels for perfusion of blood across the orienting balloon when the orienting balloon is inflated. In one embodiment as illustrated in FIG. 4b , a perfusion lumen 402 is provided to perfuse blood across the anchor balloon 409 when the anchor balloon 409 is inflated. In another embodiment as illustrated in FIG. 4c , a perfusion lumen 405 is provided to perfuse blood across the orienting balloon 407 when the orienting balloon 407 is inflated. In one embodiment as illustrated in FIG. 5 multiple anchor balloons 501, 502 may be present. In another embodiment illustrated in FIG. 6, at least one anchor balloon may be present in each flexible portion of the shaft, e.g., a first anchor balloon 601 is present in a first flexible portion 611 and a second anchor balloon 602 is present in a second flexible portion 612. The first anchor balloon 601 is inflated using the first lumen 621 and the second anchor balloon 602 is inflated using the second lumen 622, thereby the first anchor balloon 601 may be inflated or deflated independently from the inflation or deflation of the second anchor balloon 602, and vice versa. In another embodiment (not shown), a single lumen connects a plurality of anchor balloons, whereby all anchor balloons inflate or deflate simultaneously. In one embodiment, one or more anchor balloons may be anchored to the introducer catheter 624 depending on how the orienting balloon 607 advances through the vasculature of a patient's body. More than one anchor balloon may be inflated independently, if the orienting balloon experiences increased resistance. In another embodiment, an orienting balloon may be present at the distal edge of the introducer catheter. In another embodiment, an anchoring balloon may be located in a distal portion of the introducer catheter. An anchoring balloon located on the introducer catheter, upon inflation, may press against the outer surface of the transporter catheter to anchor the introducer catheter to the transporter catheter.

In yet another embodiment of the invention shown in FIG. 7, an introducer catheter to which a transporter catheter is anchored is advanced using hydraulic pressure. The system 70 comprises the transporter catheter with a shaft 701, an orienting balloon 707 located at a distal end of the shaft 701, a hydraulic fluid lumen 721, hydraulic fluid 722, and a piston 723 movably disposed in the hydraulic fluid lumen and connected to the shaft 701 of the transporter catheter. The piston forms a seal with an interior surface of the hydraulic fluid lumen. A hydraulic driver, e.g., a syringe, that generates hydraulic pressure against the piston sufficient to advance the shaft 701 of the transporter catheter, is used. The anchor balloon 709, which is connected to the shaft 701, advances with the shaft. Upon inflation, the anchor balloon 709 is anchored to the inner surface 725 of the introducer catheter 724, and thereby the advancement of the anchor balloon 709 also advances the introducer catheter 724 through a patient's vasculature. In one embodiment, the method of advancing the introducer catheter a first distance inside a patient's vasculature comprises the following steps: (a) positioning the transporter catheter inside the introducer catheter; (b) inflating the orienting balloon; (c) adjusting the position of the transporter catheter whereby the orienting balloon is substantially outside the distal end of the introducer catheter; (d) inflating the anchor balloon to anchor the transporter catheter to the inside surface of the lumen of the introducer catheter; (e) applying hydraulic pressure to the piston to advance the introducer catheter. In another embodiment, after advancing the introducer catheter a first distance using hydraulic pressure, the introducer catheter is advanced a second distance using the following method: (i) deflating the anchor balloon; (ii) reducing the hydraulic pressure; (iii) repositioning the transporter catheter inside the lumen of the introducer catheter; (iv) inflating the anchor balloon to anchor the transporter catheter to the introducer catheter; and (v) applying hydraulic pressure again. Steps (i) to (v) may be repeated to continue advancing the catheter system. In one embodiment, the inflation medium comprises a 1:2 mixture of contrast medium and normal saline solution.

In one embodiment, the length of the transporter catheter 100 may be from about 100 cm to about 250 cm. The end use and the length of the introducer catheter may determine the length of the transporter catheter. By way of illustration only and not by way of limitation, and depending on physiology of a patient, a cerebral vasculature application may warrant a transporter catheter length from about 100 cm to about 150 cm; a coronary vasculature application may warrant a transporter catheter length from about 100 cm to about 160 cm in length; a peripheral vasculature application may warrant a transporter catheter length from about 70 cm to about 100 cm in length; a renal vasculature application may warrant a transporter catheter length from about 60 cm to about 90 cm in length; and a hepatic vasculature application may warrant a transporter catheter from about 70 cm to about 100 cm in length. In one embodiment, the outer diameter of the shaft 101 of the transporter catheter 100 may range from about 2 French to about 12 French, or higher. In another embodiment, the outer diameter of the shaft 101 of the transporter catheter 100 may be in the range from about 4 mm to about 10 mm, or higher. However, the dimensions of the shaft 101 of transporter catheter 100 may vary in accordance with various applications of the catheter system and size of the introducer catheter.

In one embodiment, the difference between the outer diameter of the shaft of the transporter catheter and the inner diameter of the introducer catheter is less than 0.5 mm. In another embodiment, the outer diameter of the shaft of the transporter catheter is about 0.5 mm smaller than the inner diameter of the introducer catheter. In another embodiment, the outer diameter of the shaft of the transporter catheter is about 1 mm to about 2 mm smaller than the inner diameter of the introducer catheter. In yet another embodiment, outer diameter of the shaft of the transporter catheter is about half of the inner diameter of the introducer catheter. In another embodiment, the length of the transporter catheter may be from about 20 cm to about 60 cm. In yet another embodiment, the transporter catheter may have short lengths, e.g., in the range of about 3 cm to about 10 cm. In another embodiment, the transporter catheter may have length in the range of about 10 cm to about 300 cm. In one embodiment, an orienting balloon may be located about 3 mm from the distal tip of the transporter catheter. In another embodiment, the gap between the distal end of the anchor balloon and the proximal end of the orienting balloon may be in the range of about 2-10 mm. In another embodiment, the gap between the distal end of the anchor balloon and the proximal end of the orienting balloon may be in the range of about 3-5 mm. In one embodiment, the outer diameter of the orienting balloon is about the same as the outer diameter of the introducer catheter. In another embodiment, the outer diameter of the orienting balloon is greater than the outer diameter of the introducer catheter. In one embodiment, the orienting balloon is compliant. In another embodiment, the anchor balloon is non-compliant. In yet another embodiment, the orienting balloon is semi-compliant.

The distal end 103 of the shaft 101 may or may not be tapered. In one embodiment, shaft 101 may have a taper, with the proximal end 102 having larger diameter than the distal end 103. The end use and the inside diameter of the introducer catheter may determine the outer diameter of the shaft 101. In one embodiment, shaft 101's inner diameter may range from about 1 French to about 3 French, or higher. If shaft 101 is to receive a guidewire 108, the inner diameter of the shaft will need to be proportioned accordingly. In one embodiment, guidewires up to 1.4 French in diameter may be used. In another embodiment, guidewires may not be used in conjunction with the transporter catheter and the transporter catheter may not have lumen 105 for a guidewire. In one embodiment, the transporter catheter may deliver the introducer catheter to the desired location over a guidewire. In another embodiment, the transporter catheter may deliver the introducer catheter to the desire location without the use of the guidewire. After the introducer catheter is positioned, stylet(s) if present may be removed, then the orienting balloon and the anchor balloon may be deflated by means of a hand-held syringe or other means. In one embodiment, the transporter catheter is configured to track over a 0.009-0.014″ guidewire. In another embodiment, the transporter catheter may have a central lumen capable of accommodating guidewires of various diameters (e.g., guidewire with a diameter in the range 0.010″ to 0.065″). In one embodiment, the transporter catheter may be structured in a “rapid exchange” configuration. In another embodiment, the transporter catheter may be structured in an “over-the-wire” configuration. In another embodiment, the transporter catheter may not include an orienting balloon, and may include at least one anchor balloon and/or may include at least one mechanical connector, said anchor balloon and/or mechanical connector located at the distal end of the transporter catheter. The at least one anchor balloon and/or the at least one mechanical connector anchors the distal end of the transporter catheter to the outer catheter. In one embodiment, the distal end of the transporter catheter is anchored to the distal end of the outer catheter. In another embodiment, the at least one anchor balloon and/or the at least one mechanical connector are located in the distal end portion of the transporter catheter. In yet another embodiment, the distal end portion of the transporter catheter is anchored to the distal end portion of the outer catheter.

The material for shaft 101, lumens 104, 105 and 106, orienting balloon 107 may contain any one or more of the following additives. By way of illustration only and not limitation, such additives may include radiopaque fillers, slip additives, and hydrophilic coatings. In one embodiment, silicon provides hydrophilic coating. In another embodiment, the material for shaft 101 comprises a particulate radiopaque filler material. In one embodiment, an anchoring mechanism to anchor the transporter catheter to the outer catheter is a friction-based mechanism between an outer surface of the transporter catheter and an inner surface of the outer catheter. In another embodiment, the anchor balloon may be made of materials and/or coated with materials that provide frictional resistance to reduce slippage. In one embodiment, the anchor balloon may be made of polyurethane. In another embodiment, the anchor balloon may have serrations 801 as illustrated in FIG. 8a and/or raised projections 802 as illustrated in FIG. 8b to enhance the anchoring capability of the anchor balloon to the inside of the introducer sheath after the anchor balloon is inflated. The serrations and/or raised projections may have spiral shape 801 as shown in FIG. 8a , linear shape 802 as shown in FIG. 8b , and other shapes, see for example, circular ring shape 803 (see FIG. 8c ) or crisscross checkered shape 804 (see FIG. 8d ). The projections may have inserts, e.g., wires. The wires or wire segments may be made from various materials, and may each be made of the same materials or materials with similar material properties, or different materials having different properties. As an example, such wires or wire segments may be formed from stainless steel. The material of wires may be stiffer than the materials forming the wall of the balloon. In another embodiment, the wires may be made of Nitinol. The projections enhance the anchoring capability of the anchor balloon to the inside surface of the outer catheter, such as an introducer catheter, by coarsening the outer surface of the anchor balloon and anchoring the outer surface of the anchor balloon to the inner surface of the introducer catheter. The wire or wire segments forming the projections may also have any cross-sectional geometric shape, including for example, circular, square, or triangular, and different projections may have different cross-sectional shapes. Rounded shapes and/or smooth edges may help to prevent the wire or wire segment forming the projection from perforating the wall of the anchor balloon. In one embodiment, the wire or wire segments may be hollow to allow for passage of blood, thereby preventing occlusion of blood when the anchor balloon is inflated. In another embodiment, the inner surface of the outer catheter may be configured at a distal portion of the outer catheter to enhance frictional anchoring capability, e.g., the inner surface of the outer catheter at the distal portion may have a layer of material with higher friction coefficient or may have knurling or serrations, or may otherwise treated so as to increase frictional resistance in that portion of the inner surface of the outer catheter.

In one embodiment, the wires or wire segments comprise a material that is radiopaque (either a homogeneous material or a material that is non-radiopaque, but is provided with a radiopaque coating), and thus visible under fluoroscopy. Making the projections visible may also allow the clinician to better discern the location and orientation of the anchor balloon, as well as the position of the anchor balloon before inflating and anchoring the balloon to the inner surface of the introducer catheter. In another embodiment, the wall of the anchor balloon may comprise radiopaque particles.

In one embodiment, at least one mechanical connector is used to connect and anchor the transporter catheter and the introducer catheter. In another embodiment, the transporter catheter comprises a mechanical connector to anchor the transporter catheter to the inner surface of the introducer catheter. In yet another embodiment, the transporter catheter comprises a mechanical connector to anchor the transporter catheter to the introducer catheter at or near the distal edge of the introducer catheter. In another embodiment, the transporter catheter and/or the introducer catheter comprises at least one mechanical connector located in the distal portion of the transporter catheter and/or the distal portion of the introducer catheter. In one embodiment, a handle at the proximal end of the transporter catheter may be used to engage the mechanical connector thereby enabling the anchoring of the transporter catheter to the introducer catheter. The handle at the proximal end of the transporter catheter may also be used to disengage the mechanical connector thereby allowing the removal of the transporter catheter from the introducer catheter. In another embodiment, a handle at the proximal end of the introducer catheter may be used to engage or disengage the mechanical connector. In one embodiment, the mechanical connector is a circular cage of a matrix of round or flat wires wherein the diameter of the cage can be increased or decreased mechanically. In another embodiment, diameter of the cage may be increased or decreased, e.g., by rotating the handle at the proximal end of the transporter catheter, whereby when the handle is rotated in one direction, the cage is torqued to open and increase its diameter, and when the handle is rotated in other direction, the cage is torqued to close and decrease its diameter. The diameter of the cage is increased until it presses against the inner surface of the introducer catheter to anchor the transporter catheter to the introducer catheter. In another embodiment, the mechanical connector may be located on the introducer catheter and the mechanical connector engages, e.g., presses against or locks the transporter catheter to anchor the introducer catheter to the transporter catheter.

In operation, a transporter catheter and an outer catheter may be advanced from various arterial access sites, such as femoral, radial, brachial, axillary and carotid artery to gain percutaneous or operative entry to arterial circulation. In one embodiment, once access is gained, a device is advanced from the access point via the aorta to the desired target location for diagnostic or interventional procedure. Introduction of a catheter directly through an arteriotomy increases the possibility of abrasion by the catheter edge against the inner arterial wall (also known as intima). To reduce the risk of this possible interaction, a guidewire is typically first advanced through an arteriotomy. The guidewire is typically a soft tipped, lower profile, flexible object, e.g., with a tip that is atraumatic. The placement of the guidewire and introduction of the catheter over the guidewire centers the catheter in the lumen of the artery and reduces the risk of abrasion of the catheter against the inner arterial wall. Despite the decreased risk to the intima of the arterial circulation because of guidewire placement and over-the-wire advancement, there still remains a risk of abrasion of the internal wall of the arterial vessels by the overhang of the catheter in view of the fact that the guidewire is frequently significantly smaller in diameter compared to the catheter. This abrasive effect of the catheter, which is generally termed as “razor defect”, may lead to dislodgement of elements from the inner arterial wall, such as atherosclerotic as well as other debris. Liberated atherosclerotic, as well as other debris, then may follow the arterial circulation and may lodge into a small distal branch based on the size of such debris. This event may lead to tissue death or necrosis, which may lead to permanent organ dysfunction, including ischemic necrosis of the bowel because of an athero-embolic event, acute kidney injury because of a similar embolic event, as well as cerebrovascular events from liberation of atheroma that may be caused by catheter transit through the ascending aorta and the aortic arch. An embodiment of the present invention comprising the orienting balloon generally provides resolution of the overhang, reducing the potential of the transitions, and hence reducing the razor effect and lowering the risk of embolic events that may result from catheter transit.

In operation as illustrated in FIG. 9, the orienting balloon 907 orients and maneuvers the catheter system comprising the introducer catheter 924 and the transporter catheter 901 through the curves of the vasculature 931 in a patient's body. The orienting balloon 907 protrudes outside the introducer catheter 924. In one embodiment, about 50% of the orienting balloon protrudes outside the introducer catheter 924. In another embodiment, more than 50% of the orienting balloon 907 protrudes outside the introducer catheter. In yet another embodiment, about 80% of the orienting balloon 907 protrudes outside the introducer catheter 924. In another embodiment, less than 50% of the orienting balloon 907 protrudes outside the introducer catheter 924. In one embodiment, the orienting balloon may be inflated using a pressure from about 2 atmospheres to about 10 atmospheres or higher. In another embodiment, the orienting balloon may be inflated to a pressure in the range 12-15 atmospheres. In another embodiment, the orienting balloon is inflated using a pressure of about 4 atmospheres. In one embodiment, the diameter of protruding portion of the orienting balloon, that protrudes out from the introducer catheter may be larger than the outer diameter of the introducer catheter thereby substantially reducing or eliminating a potential razor effect of the edge of the introducer catheter. The anchor balloon 909 anchors the shaft of the transporter catheter 901 to the inner surface of the lumen of the introducer catheter 924. In one embodiment, a guidewire 908 may be present. In another embodiment, segment 911 between the anchor balloon 909 and the orienting balloon 907 may be more flexible than segment 901 of the transporter catheter. The catheter system may be advanced by pushing and/or torqueing the introducer catheter 924, or the transporter catheter 901, or both. If the catheter system is advanced by pushing the introducer catheter, the wall of the introducer catheter should have enough axial strength to be pushed through the patient's vasculature via a force applied at its proximal end (“pushability”). It is also desirable for the introducer catheter to be capable of transmitting a torque applied at the proximal end along the length of the shaft through to the distal end (“torqueability”). An introducer catheter should also have enough flexibility to conform substantially to the patient's vasculature and yet resist kinking as it is pushed and/or torqued through the patient's vasculature and conforms to the patient's vasculature.

The wall of an introducer catheter 924 that is advanced by pushing the introducer catheter is thick, and increasing the bore size of an introducer catheter having a given overall diameter requires utilizing a thinner wall. Now that catheters are used in smaller and smaller vessels and body lumens, there is a growing need to use introducer catheters that have a smaller wall thickness. However, a thin-walled introducer catheter that is pushed through the patient's vasculature is more likely to collapse upon itself or kink when a push force and/or torque is applied at its proximal end. On the other hand, if the introducer catheter 924 is pulled through the patient's vasculature by an anchor balloon 909 of a transporter catheter, then the wall of the introducer catheter 924 may be relatively thinner. A thin wall may be used because when the introducer catheter 924 is pulled through the patient's vasculature 931, a pulling tensile force is applied to the wall of the introducer catheter 924. The tensile force has a stretching effect on the wall of the introducer catheter and prevents kinking of the wall of the introducer catheter 924. On the other hand, if the introducer catheter 924 is pushed through the patient's vasculature, a compressive force is applied to the wall of the introducer catheter 924. If the introducer catheter 924 experiences resistance and push-back from a patient's lumen, the compressive force could result in kinking of the wall of the introducer catheter 924. In one embodiment, pushing the transporter catheter to advance the outer catheter to a desired location in a patient's body results substantially in pulling the outer catheter to the desired location. In one embodiment, thickness of the wall of the introducer catheter 924 is less than thickness of the wall of the transporter catheter 901. In another embodiment, the wall of the introducer catheter 924 is more flexible than the wall of the transporter catheter 901. In another embodiment, the wall of the transporter catheter 901 comprises a structure of wires to increase the stiffness of the wall of the transporter catheter. In another embodiment, the wall of the introducer catheter 924 does not comprise a structure of wires. In yet another embodiment, the introducer catheter 924 in the proximal end portion of the introducer catheter may be more flexible than the transporter catheter 901 in the proximal end portion of the transporter catheter. In one embodiment, thickness of the wall of the introducer catheter 924 is less than 0.2 mm. In another embodiment, the thickness of the wall of the introducer catheter 924 is less than 0.1 mm. In yet another embodiment, the thickness of the wall of the introducer catheter 924 is less than 0.5 mm. In one embodiment, the outer wall of the introducer catheter 924 is provided with a hydrophilic coating to reduce friction between the outer wall of the introducer catheter 924 and the inner wall of a lumen 931 through which the introducer catheter is being advanced.

FIG. 10a is a schematic of the forces that act on the introducer catheter when a user pushes the introducer catheter in direction 133 at the proximal end of the introducer catheter 124 using a handle 132. The push force 151 on the wall of the introducer catheter has a horizontal component 153 that advances the introducer catheter 124 through the vasculature 131 of the patient's body, and a vertical component 152 that presses the wall of the introducer catheter 124 against the wall of the vasculature 131. Because component 152 is directed towards the wall of the vasculature 131, the component 152 adds frictional resistance and drag to the introducer catheter as it advances through the vasculature. Because of the additional frictional resistance, a greater push force is required, thereby requiring a thicker wall for the introducer catheter so that the introducer catheter does not collapse or kink. A greater push force also results in additional frictional resistance because of a larger vertical component 152. Total frictional resistance depends on the contact area between the introducer catheter and the vasculature and therefore depends in part on the length of the introducer catheter that is inserted into the vasculature of a patient's body. Because of the compounding of the frictional resistance with increase in push force, the length to which an introducer catheter can be pushed inside the vasculature may be limited.

FIG. 10b is a schematic of the forces that act on the introducer catheter as it is pulled by the anchor balloon of the transporter catheter when the user pushes the transporter catheter to advance the introducer catheter. When a user pushes the transporter catheter 201 and with it, its anchor balloon 209 in the direction 233, the anchor balloon exerts a pull force 251 on the wall of the introducer catheter 124. The pull force 251 on the wall of the introducer catheter has a horizontal component 253 that advances the introducer catheter 124 through the vasculature 131 of the patient's body, and a vertical component 252 that pulls the wall of the introducer catheter 124 away from the wall of the vasculature 131. Because component 252 is directed away from the wall of the vasculature, the component 252 reduces the frictional resistance and the drag on the introducer catheter as it advances through the vasculature. Consequently, a smaller push force is required on the transporter catheter to advance the catheter system through the vasculature. Furthermore, because the walls of the introducer catheter experience a pull force at the distal end (rather than a push force at the proximal end), the possibility of kinking the wall of the introducer catheter is reduced, and a thinner wall may be used for the introducer catheter. The transporter catheter is removed after the introducer catheter is positioned at a desired location. Thus, for a given outer diameter of an introducer catheter and by using a transporter catheter to advance the introducer catheter (or to advance any other outer catheter such as a sheath, a guide catheter, or a mother catheter), the user may use an introducer catheter with a thinner wall, thereby providing a larger diameter of its inner lumen. In one embodiment, the transporter catheter may be used to pull the introducer catheter through the tortuosity of arteries, including celiac and mesenteric arteries. In another embodiment, a catheter system comprising the transporter catheter may be used to perform revascularization as well as devascularization in cerebral circulation. In yet another embodiment, a catheter system comprising the transporter catheter may be used to cannulate a middle coronary vein, while implanting a CRT-D device or other devices. In one embodiment, a catheter system comprising the transporter catheter may be used in a remote tele-robotic procedure, such as stroke management. In another embodiment, a system comprising the transporter catheter may be used to assist in the maneuvering and positioning of an endoscopy tube or a colonoscopy tube inside a tract of a digestive system of a patient.

In another embodiment (see FIGS. 11 and 12) comprising a mother catheter 166 and an inner support catheter (daughter or child catheter) 165 advanced on a guidewire 168, the inner support catheter 165 is advanced by placing a transporter catheter 161 inside a lumen of the inner support catheter 165, with the transporter catheter having an orienting balloon 167 protruding from the tip of the inner support catheter and another balloon 169, which is inside the lumen of the inner catheter 165 providing anchoring. Using this multi-balloon transporter catheter 161 to advance the inner catheter 165, the double balloon catheter composite may be advanced through an adverse arterial lumen, beyond the stenosis 162. After the inner support catheter has been successfully placed beyond the stenosis 162, the transporter catheter is withdrawn after deflating the orienting and the anchor balloons. Then a stent 164 (see FIG. 13) or other hardware may be placed through the inner support catheter 165 distal to the stenosis 162 or in another preferred position. Subsequently the inner support catheter is withdrawn and the stent 164 may be then positioned usually by pulling the stent 164 to the site of interest and deploying the stent 164 (FIG. 13). In one embodiment, at least one hole may be provided in the structure of the inner support catheter to provide for perfusion of blood from outside the inner support catheter into the inner support catheter. In one embodiment, the transporter catheter is inserted in the outer catheter and the orienting balloon is left partially protruding out of the tip of the outer catheter. The orienting balloon is then inflated with sufficient pressure using a fluid to achieve a certain diameter. In one embodiment, the diameter of the inflated orienting balloon is at least equal to the inner diameter of the outer catheter tip. In another embodiment, the diameter of the protruding portion of the orienting balloon is at least equal to the outer diameter of the outer catheter tip. In yet another embodiment, the diameter of the protruding portion of the orienting balloon is greater than the outer diameter of the outer catheter tip. A guidewire may be placed through the orienting balloon before, during or after inflation.

The inner support catheter may include a hydrophilic coating to reduce friction between the arterial lumen and the external surface of the inner support catheter. The wall of the inner support catheter can be made thin whereby the diameter of the inner lumen of the support catheter is large and the outer dimensions of the inner support catheter conforms to the geometry of the coronary artery or other vessels. Because the transporter catheter is used to advance the inner support catheter, the inner support catheter does not require as much structure (such as larger wall thickness) to transmit longitudinal axial forces.

In one embodiment, the transporter catheter has at least one balloon that functions as both the orienting balloon and the anchor balloon. The transporter catheter comprises a shaft, said shaft comprising a proximal end and a distal end; at least one balloon positioned adjacent to the distal end of the shaft, the at least one balloon (see FIG. 14a-d ) comprising a distal portion 855 and a proximal portion 856; the distal portion 855 of the at least one balloon, upon inflation, has a surface configured for smooth movement of the transporter catheter through a patient's vasculature, and the proximal portion 856 of the at least one balloon, upon inflation, has a surface configured for anchoring the transporter catheter to an outer catheter 224 (see FIG. 15); wherein, in operation, the transporter catheter is located within a lumen 226 of the outer catheter 224 and the proximal portion 856 of the at least one balloon upon inflation presses against an inner surface 857 of the lumen of the outer catheter thereby anchoring the transporter catheter 859 near the distal end of the transporter catheter to the outer catheter 224 near a distal end of the outer catheter (see FIG. 15); and, thereafter, when the transporter catheter is pushed and/or torqued to advance the outer catheter to a desired location in the patient's vasculature, the transporter catheter in effect pulls the outer catheter to the desired location in a patient's vasculature. In another embodiment, an interface 858 between the distal portion and the proximal portion of the at least one balloon comprises a radiopaque marker. In yet another embodiment, the distal portion of the at least one balloon is smooth and contoured to assist with smooth advancing of the transporter catheter through the vasculature of the patient's body. In one embodiment, the surface of the distal portion of the at least one balloon is coated with a friction-reduction coating. In another embodiment, the proximal portion of the at least one balloon, after anchoring to the inner surface of the lumen of the outer catheter, reduces slippage or pushback of the transporter catheter backwards into the lumen of the outer catheter when the at least one balloon experiences increased resistance within the patient's vasculature. In yet another embodiment, the surface of the distal portion of the at least one balloon comprises channels for perfusion of blood across the at least one balloon after the at least one balloon is inflated.

In one embodiment (see FIG. 16), a diameter of a distal portion 860 of the at least one balloon, upon inflation, is greater than an outer diameter of the outer catheter, thereby substantially reducing or eliminating a potential razor effect of an edge of the outer catheter. In another embodiment, the proximal portion of the at least one balloon anchors the transporter catheter to the outer catheter using a friction-based mechanism between an outer surface of the proximal portion of the at least one balloon and an inner surface of the lumen of the outer catheter. In one embodiment, the friction-based mechanism comprises at least serrations 851 (FIG. 14a ) and/or raised projections 852 (FIG. 14b ), wherein the serrations and/or the raised projections have shapes comprising spiral 851 (FIG. 14a ), linear 852 (FIG. 14b ), circular 853 (FIG. 14c ), crisscrossed 854 (FIG. 14d ) or combinations thereof. In another embodiment, the friction-based mechanism comprises at least an outer layer covering at least partially the outer surface of the proximal portion of the at least one balloon that comes in contact with the inner surface of the lumen of the outer catheter, said outer layer comprising materials providing higher frictional resistance. In one embodiment, the outer layer may comprise of etched polymeric material, e.g., etched polytetrafluoroethylene (PTFE) layer. In another embodiment, a layer of interlaced and/or braided wires may be embedded on the outer surface of the balloon or the wires may be glued or otherwise connected to the outer surface of the at least one balloon.

In one embodiment, the transporter catheter comprises at least two balloons (see FIG. 17). A first balloon 867 is located near the distal end of the transporter catheter, said first balloon 867 having a distal portion 855 that facilitates the orienting and the maneuvering of the transporter catheter and a proximal portion 856 that anchors the transporter catheter to the inner surface of the outer catheter 224. A second balloon 869 is an anchor balloon and is located near the first balloon 867. In one embodiment of a method to advance the outer catheter 224, both the first balloon and the second balloon may be inflated separately and independently to anchor the transporter catheter to the outer catheter. Next the transporter catheter is pushed and/or torqued to advance the outer catheter substantially near a location of treatment in a patient's vasculature. Subsequently, the second balloon may be deflated and upon further pushing and/or torqueing of the transporter catheter, the first balloon pulls the distal end of the outer catheter to the location of the treatment site or beyond the treatment site. Subsequently the first balloon may be deflated and the transporter catheter removed from inside the outer catheter and then a treatment system may be advanced inside the outer catheter to a location at the treatment site or beyond the treatment site. In another embodiment of the method, the first and the second balloon may be deflated and the transporter catheter may be removed after the outer catheter is advanced to a desired location.

FIG. 18a depicts a cross-sectional view of an embodiment of a shaft of the transporter catheter as shown in an embodiment depicted in FIG. 15. The transporter catheter is comprised of a tubular polymeric inner liner 182, a torque-transfer layer 184, a core 186 comprised of a melt-processing polymer, and a heat-shrink layer 188. Lumen 191 provides for passage of a guidewire and lumen 192 provides for inflating or deflating the orienting balloon. FIG. 18b depicts a cross-section view of an embodiment of a shaft of the transporter catheter as shown in an embodiment depicted in FIG. 17. Lumen 193 provides for inflating or deflating the anchor balloon 869.

In one embodiment, the transporter catheter is steerable using pull-wires. In another embodiment, the pull-wires comprise at least one flat wire 190 disposed longitudinally along the length of the transporter catheter (See FIGS. 18c and 18d ). A flat pull-wire 190 typically has a rectangular cross section, though the cross section of the pull-wire need not be perfectly rectangular. In another embodiment, the cross-sectional shape of the pull-wire may be oval or circular. A transporter catheter 100 (see FIG. 1) may include an elongated pull-wire extending through a pull-wire lumen of the shaft 101 of the transporter catheter 100 and terminating within the distal end portion of the shaft. In one embodiment, the pull-wire has a proximal end operatively connected to a handle assembly and a distal end anchored to the distal end portion of the transporter catheter. In another embodiment as shown in FIG. 19, the steerable transporter catheter may include a pull-wire anchor ring or steering ring 195 mechanically coupling a distal end of the pull-wire to the distal end portion of the transporter catheter. In one embodiment, the steering ring 195 may be located at or near the distal end 115 of the anchor balloon 109. In another embodiment, the steering ring 195 may be located under the anchor balloon 109. In yet another embodiment, the steering ring 195 may be located near the proximal or the distal end of the orienting balloon 107. In one embodiment, the torque-transfer layer 184 may be disposed between the inner liner 182 and the pull-wire 190. In another embodiment, the torque-transfer layer may be disposed between the pull-wire 190 and the heat-shrink layer 188. In another embodiment, the heat shrink layer may not be present. In one embodiment the pull-wire 190 may be covered with lubricious materials before placement inside the transporter catheter. The lubricious materials comprise silicone and other lubricious materials. In another embodiment, the pull-wire 190 may be smooth and coated with a lubricious layer. In one embodiment, the pull-wire is made of stainless steel. In another embodiment, more than one pull-wire may be used. In another embodiment, two pull-wires may be used and spaced 180 degrees apart (See, e.g., FIG. 18d ). In one embodiment, the pull-wires 190 are connected to at least one anchor ring 195 located near the distal end of the introducer (see FIG. 19). The proximal ends of the pull-wires 190 are operably connected to a steering mechanism (not shown) allowing for the steering of the transporter catheter 100 during operation. In one embodiment, a pull-wire may be housed inside a polymeric tube 196 forming a lumen.

In one embodiment, the inner liner 182 is a polymeric material, such as polytetrafluoroethylene (PTFE) or etched PTFE. The inner liner 182 may also be made of other melt-processing polymers, including, without limitation, polyether block amides, nylon and other thermoplastic elastomers. Once such elastomer is Pebax (Pebax is a registered trade mark and Pebax is made by Arkema, Inc.). Pebax of various durometers may also be used, including without limitation, Pebax 30D to Pebax 70D. In one embodiment, the core 186 of the shaft is made of an extruded Pebax or PTFE tubing. The melt-processing polymer of the core 186 occupies a plurality of voids of the wire mesh in the torque-transfer layer. The core 186 may also be made of other melt-processing polymers, including, without limitation, etched PTFE, polyether block amides, nylon and other thermoplastic elastomers, of varying durometers. The core 186 may also comprise more than one layer, including, for example, two or more tubes of a melt-processing polymer (see FIG. 19).

In one embodiment, a method for intravascular treatment using a transporter catheter, comprises the steps of: (i) assembling a system comprising a transporter catheter and an outer catheter, the transporter catheter comprising a shaft having at least a first wall, a proximal end, a distal end and at least one internal channel for a guidewire, the outer catheter comprising a substantially cylindrical lumen having a second wall, a proximal end and a distal end, the transporter catheter extending within the lumen of the outer catheter with the distal end of the transporter catheter substantially aligned with the distal end of the outer catheter, an anchoring mechanism displaced in an operative coupling with the transporter catheter and/or the outer catheter whereby the anchoring mechanism anchors at least a distal portion of the transporter catheter to at least a distal portion of the outer catheter, the anchoring mechanism controllably actuated for anchoring or for removal of anchoring of the transporter catheter to the outer catheter; (ii) extending a guidewire along the internal channel of the transporter catheter with a proximal end of the guidewire extending beyond the proximal end of the of the transporter catheter and a distal end of the guidewire extending beyond the distal end of the transporter catheter; (iii) advancing the distal end of the guidewire towards a desired location in a vessel of interest at a treatment site; (iv) controlling said anchoring mechanism to anchor at least the distal portion of the outer catheter to at least the distal portion of the transporter catheter; (v) advancing the system by pushing and/or torqueing at least the transporter catheter along the guidewire towards the treatment site until the system is brought in alignment with or beyond the treatment site; (vi) actuating the anchoring mechanism to remove the anchor hold between the transporter catheter and the outer catheter; (vii) removing the transporter catheter from inside the outer catheter; and (viii) advancing a treatment system inside the outer catheter to a location at the treatment site or beyond the treatment site.

In one embodiment, the transporter catheter 100 is manufactured via an extrusion process. Given that extrusion processes are well known in the art, the general process is not discussed in detail herein. In general, the extrusion process begins by heating the polymer until melted. The melted polymer is then forced under pressure through an extrusion tip and die. As the melted polymer exits the extrusion tip and die, it is cooled. A typical cooling method employs a water bath. The cooling step solidifies the device with the desired dimensions.

Shaft 101 and lumens 104, 105 and 106 may be manufactured using any commercially available catheter materials. Materials may include, without limitation, polyethylene, polyamide, and urethane. It may be also possible to use polyolefin, such as polypropylene; polyesters including polyamide and polyethylene terephthalate; fluorine-based polymer including PTFE (polytetrafluoroethylene); PEEK (polyether ether ketone); polyimide; synthetic resin elastomers including an olefinic elastomer (e.g., a polyethylene elastomer and a polypropylene elastomer), polyamide elastomer, styrenic elastomer (e.g., a styrene-butadiene-styrene copolymer, a styrene-isoprene-styrene copolymer, a styrene-ethylene butylene-styrene copolymer); polyurethane, urethane-based elastomer, and fluorine-based elastomer; synthetic rubber, including urethane rubber, silicone rubber, and butadiene rubber. The material chosen will depend on the end use of the catheter, the size of the vessel to be accessed, and/or whether or not a stylet or stylets will be used to assist during insertion and advancement of the catheter system. The desired end use will determine the degree of stiffness, flexibility, strength and/or slipperiness of the material(s) to be used. Orienting balloon 107 and anchor balloon 109, may be manufactured using any commercially available balloon materials. Materials include, without limitation, latex, silicone, ethylvinylacetate, and urethane.

It should be appreciated that several of the above-disclosed and other features and functions, or alternatives or varieties thereof, may be desirably combined into many other different systems or applications. Also, it should be appreciated that various alternatives, derivatives, modifications, variations or improvements thereof or therein may be subsequently made by those skilled in the art, which are also intended to be encompassed by the following claims.

In the description above, for the purposes of explanation, certain requirements and certain details have been included in order to provide an understanding of the embodiments. It will be apparent however, to one skilled in the art, that one or more other embodiments may be practiced without some of the requirements or details. The particular embodiments described are not provided to limit the invention, but merely to illustrate it. The scope of the invention is not to be determined by the specific examples provided above. In other instances, well-known structures, devices, and operations have been shown in block diagram form or without detail in order to avoid obscuring the understanding of the description. Where appropriate, reference numerals or terminal portions of reference numerals have been repeated among the figures to indicate corresponding or analogous elements, which may optionally have similar characteristics.

It should also be appreciated that reference throughout this specification to “one embodiment”, “an embodiment”, “one or more embodiments”, or “different embodiments”, for example, means that a particular feature may be included in the practice of the invention. Similarly, it should be appreciated that in the description various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects may lie in fewer than all features of a single disclosed embodiment. In another situation, an inventive aspect may include a combination of embodiments described herein or in a combination of fewer than all aspects described in a combination of embodiments. 

The invention claimed is:
 1. A transporter catheter comprising: a shaft, said shaft comprising a proximal portion and a distal portion; at least one anchor formed on the distal portion of the shaft, the at least one anchor selected from a group consisting of an inflatable balloon or a mechanical connector, the at least one anchor capable of engaging with a wall of an outer catheter to form a catheter system comprising the transporter catheter inside the outer catheter, the transporter catheter configured to be pushed and/or torqued to advance and maneuver the catheter system through a patient's vasculature; and the at least one anchor configured to apply a pull force on the outer catheter when the transporter catheter is pushed and/or torqued, a first component of the pull force pulling the outer catheter towards a desired location in the patient's vasculature, and a second component of the pull force pulling the wall of the outer catheter away from a wall of the patient's vasculature.
 2. The transporter catheter of claim 1, wherein the shaft comprises at least one internal channel for a guidewire.
 3. The transporter catheter of claim 1, further comprising an orienting balloon formed on the shaft at a distal end of the shaft, wherein at least a portion of the orienting balloon protrudes outside a distal end of the outer catheter.
 4. The transporter catheter of claim 1, further comprising a radio-opaque marker on at least a distal portion of the transporter catheter.
 5. The transporter catheter of claim 1, wherein the shaft comprises a varying degree of stiffness, a degree of stiffness of the varying degrees of stiffness at the proximal portion of the shaft being greater than a degree of stiffness of the varying degrees of stiffness at the distal portion of the shaft.
 6. The transporter catheter of claim 5, wherein the varying degrees of stiffness of the shaft gradually reduces from a proximal end to a distal end of the shaft.
 7. The transporter catheter of claim 1, wherein the transporter catheter is steerable using at least one pull-wire disposed longitudinally along a length of the transporter catheter.
 8. The transporter catheter of claim 1, wherein the at least one balloon is made of materials and/or coated with materials that provide frictional resistance.
 9. The transporter catheter of claim 1, wherein the at least one anchor comprises the mechanical connector and wherein a handle at a proximal end of the transporter catheter is used to engage the mechanical connector with the outer catheter or to disengage the mechanical connector from the outer catheter.
 10. The transporter catheter of claim 9, wherein the mechanical connector presses against or locks with the outer catheter.
 11. The transporter catheter of claim 9, wherein the at least one mechanical connector comprises a circular cage of round or flat wire wherein a diameter of the circular cage is increased or decreased mechanically.
 12. The transporter catheter of claim 11, wherein the diameter of the cage is increased or decreased by rotating the handle at the proximal end of the transporter catheter, whereby when the handle is rotated in one direction, the cage is torqued to open and increase in diameter, and when the handle is rotated in other direction, the cage is torqued to close and decrease its diameter.
 13. The transporter catheter of claim 1, wherein the shaft comprises at least an inner layer and an outer layer.
 14. The transporter catheter of claim 13, wherein the inner layer of the shaft is made of a material more flexible than a material of the outer layer.
 15. The transporter catheter of claim 13, wherein the outer layer comprises a helical coil or a plait-matrix assembly.
 16. The transporter catheter of claim 15, wherein the plait-matrix assembly comprises a braided-wire assembly, said braided-wire assembly being formed by braiding a plurality of flat wires, circular wires, or combinations thereof.
 17. The transporter catheter of claim 16, wherein the braided-wire assembly has a proximal portion and a distal portion, and wherein the braided wire assembly has a first stiffness at the proximal portion and a second stiffness at the distal portion, and wherein the first stiffness differs from the second stiffness.
 18. The transporter catheter of claim 17, wherein the first stiffness at the proximal portion of the braided-wire assembly is greater than the second stiffness at the distal portion of the braided-wire assembly.
 19. A transporter catheter comprising: a shaft, said shaft comprising a proximal portion and a distal portion; at least one anchor formed on the distal portion of the shaft, the at least one anchor selected from a group consisting of an inflatable balloon or a mechanical connector, the at least one anchor capable of engaging with a wall of an outer catheter to form a catheter system comprising the transporter catheter inside the outer catheter, the transporter catheter configured to be pushed and/or torqued to advance and maneuver the catheter system through a patient's vasculature; the shaft comprising a varying degree of stiffness, a degree of stiffness of the varying degrees of stiffness at the proximal portion of the shaft being greater than a degree of stiffness of the varying degrees of stiffness at the distal portion of the shaft; the shaft further comprising a radio-opaque marker on at least a distal portion of the transporter catheter; and the at least one anchor configured to apply a pull force on the outer catheter when the shaft is pushed and/or torqued, a first component of the pull force pulling the outer catheter towards a desired location in the patient's vasculature, and a second component of the pull force pulling the wall of the outer catheter away from a wall of the patient's vasculature.
 20. A transporter catheter comprising: a shaft, said shaft comprising a proximal portion and a distal portion, and at least one internal channel for a guidewire; at least one anchor formed on the distal portion of the shaft, the at least one anchor selected from a group consisting of an inflatable balloon or a mechanical connector, the at least one anchor capable of engaging with a wall of an outer catheter to form a catheter system comprising the transporter catheter inside the outer catheter, the transporter catheter configured to be pushed and/or torqued to advance and maneuver the catheter system through a patient's vasculature; the at least one anchor configured to apply a pull force on the outer catheter when the transporter catheter is pushed and/or torqued, a first component of the pull force pulling the outer catheter towards a desired location in the patient's vasculature, and a second component of the pull force pulling the wall of the outer catheter away from a wall of the patient's vasculature; and wherein the transporter catheter is steerable using at least one pull-wire disposed longitudinally along a length of the transporter catheter. 